GB1493265A - Catalytic hydrocarbon conversion process - Google Patents

Abstract

1493265 Fluid catalytic cracking EXXON RESEARCH & ENG CO 29 Nov 1974 [18 March 1974] 51750/74 Heading C5E Catalyst used in the catalytic conversion of hydrocarbons overflows from the upper level 32 of a fluidized bed of catalyst in a regeneration vessel 30 into a stand pipe 42, around the bend 43 and through an upwardly inclined conduit 44 into which a transporting gas (e.g. steam) is injected from taps 46. The catalyst then passes up the vertical transferline riser 12 in admixture with the hydrocarbon charge 10 and is discharged into a gas-solid separation vessel 14 in which the catalyst is separated from the vapours 20. Separated catalyst passes into a stripping zone 22 via the open end thereof, which, as illustrated in Fig. 2 (not shown), is disposed for receiving catalyst from a lower portion of the separation vessel 14. The catalyst is stripped in the zone 22 (e.g. with steam from conduit 24) and passed through a conduit 28 into the regeneration vessel 30. The flow of catalyst in the conduit 28 is regulated by varying the size of the orifice of valve 26 and the flow of catalyst from regeneration vessel 14, through the standpipe 42, the conduit 44 and the riser 12 into the vessel 14, is effected without varying the size of any orifice through which the catalyst passes. All of the conversion can be carried out in the riser 12 or alternatively the vessel 14 can contain a fluidized bed of catalyst in which additional conversion occurs. The vessels 14 and 30 can contain gas-solids separators such as cyclones. The process can be used to produce lower boiling hydrocarbons from a feed, such as a residual oil, using a catalyst such as silica-alumina.